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Finding the Fourth Proportional to 718.08, 990.72 and 455.64

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Solution

The fourth proportional to 718.08, 990.72 and 455.64 is: 628.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.08 : 990.72 = 455.64 : x
  2. Step 2: Convert to fraction form
    718.08/990.72 = 455.64/x
  3. Step 3: Cross multiply
    718.08x = 990.72 × 455.64
  4. Step 4: Simplify right side
    718.08x = 451,411.66
  5. Step 5: Solve for x
    x = 451,411.66/718.08
  6. Step 6: Final answer
    x = 628.64

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.